v1-10: The ministry of the servant of God. This was especially true of the apostles, but true of all of us. There are two themes; suffering hardship, and displaying the character of Christ. This is in contrast to those who needed letters of commendation (3.1).

v1-2: The call to urgent response. The plea of the servant; God has so much to give. A life of disobedience is not a proper response to His grace. When God speaks "today" and "now", do not put off, do not reject, do not harden your heart (Heb 3.7, 13).

As in 5.20, Paul directly addresses those at Corinth who were in rebellion.

v3: Paul's personal discipline, to avoid all wrong, and to maintain a clear conscience. He wanted to do no-one any wrong.

v4-5: Hardships are a sign of being a servant of God. Some hardships are directly from the hand of man, e.g: beatings and imprisonments. Others are simply the result of serving the Lord, and caring for others. In all things we need "great endurance".

Great endurance; as in 12.12; 2 Tim 3.10; necessary whatever the circumstances;

• Troubles/afflictions; being pressed down; outside influences upon our lives; including the weight of circumstances, and the antagonism of people;
• Hardships/necessities; see also 12.10;
• Distresses/anguish; to be in a narrow space, restricted; used in v12;
• Beatings/stripes; to be struck, wounded;
• Imprisonments; obvious;
• Tumults/riots; circumstances of instability and disorder, used in 1 Cor 14.33;
• Labours/hard work; laborious toil, bringing weariness;
• Sleeplessness; deliberately, indicating a watching, Mark 13.33;
• Fastings/hunger; a voluntary fast.

In several of these, Paul uses a plural word, indicating that he had endured these things more than once, and possibly many times.

v6-7: Spiritual character and attitudes and resources. In Christ we find all we need that we might serve Him, and in a way that pleases Him.

• Purity; HAGNOTES; root word of holy, used in 11.3; free from contamination;
• Knowledge/understanding; GNOSIS; we must have answers for others;
• Patience/long-suffering; MAKROTHUMIA, used elsewhere in N.T., essential in the trials described in v4-5;
• Kindness; CHRESTOTES; Christian character is the key to being victorious in the various circumstances of life; see also 1 Cor 13.3;
• By the Holy Spirit; relying on His strength to see us through, to bring victory where there would otherwise be defeat;
• By sincere love; as in Rom 12.9; 1 Pet 1.22, without hypocrisy;
• In truthful speech; when there is temptation to lie or deceive, or exaggerate;
• In the power of God; see 2 Cor 2.4-5
• With weapons/armour of righteousness;
• This is not a description of stoical behaviour, or a 'stiff upper lip', but a powerful, Christ-like character.

v8: Mixed responses; we do not know how people will respond. And Paul himself had seen a variety of reactions from the people he had met. Just because we are obedient in our lives, does not mean that people will respond with faith.

v9-10: Somehow, in our trials and suffering others are blessed. We feel we have nothing to give, but others receive a great amount from us. Such is the paradox of the Christian life. Note that our circumstances are not to rule our lives. Paul describes the victory of our lives; "always rejoicing ... making many rich ... possessing everything." Our joy depends not on our outward circumstances, but upon the love and favour of God in our hearts, Hab 3.17.

v11-13: The need for openness. Paul has spoken very personally to them. Their lack of openness made them lose blessing. There is a need to be willing to learn and apply and obey, willing to put things right, to forgive, or to confess wrong; "open wide your hearts … make room for us in your hearts" (see 7.2).

v14-15: The need for separation, especially from unbelievers and their attitudes. A Christian and a non-Christian cannot be truly united. It seems the Corinthians had joined themselves to unbelievers, and separated themselves from other Christians, see 12.15 also. 

David Devenish refers to 'soul ties,' where a believer and an unbeliever are "unequally yoked." He suggests this is either a sexual or strong emotional relationship. (Demolishing Strongholds, chapter 11)

v16-18: God's promises of a special relationship with Him. This is His plan, that we might enjoy Him; but we must be separate from others who do not love the Saviour. Fellowship/communion/accord/part/agreement; Paul uses five words to describe the relationship we should have with Christ, and with each other. The words indicate a sharing together, a harmonious relationship, an agreement. Such a relationship cannot be with unbelievers.